GPT-5.2 vs Inkling vs Claude Sonnet 4.6
Too close to call on our weighted score (Claude Sonnet 4.6 62, GPT-5.2 61, Inkling 59). The right pick depends on what you value most.
OpenAIGPT-5.2
61/100- ECI153.5
- Price$1.75 / $14.00
- Context400K
Thinking MachinesInkling
59/100- ECI148.6
- Price$3.74 / $9.36
- Context1.05M
AnthropicClaude Sonnet 4.6
62/100- ECI152.3
- Price$3.00 / $15.00
- Context1M
Too close to call
It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, Inkling 59/100), so choose by what matters most for your work: GPT-5.2 for raw capability and Inkling for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.2Capabilities Index (ECI): GPT-5.2 153.5 · Claude Sonnet 4.6 152.3 · Inkling 148.6
- Lowest priceGPT-5.2GPT-5.2 $4.81 · Inkling $5.14 · Claude Sonnet 4.6 $6.00 per 1M tokens (3:1 blend)
- Longest contextInklingInkling 1,048,576 · Claude Sonnet 4.6 1,000,000 · GPT-5.2 400,000 tokens
- Widest inputsInkling and Claude Sonnet 4.6GPT-5.2: Text, Images · Inkling: Text, Images, Audio · Claude Sonnet 4.6: Text, Images, PDFs
- Self-hostingInklingPublishes downloadable weights (Apache-2.0)
| Measure | Weight | GPT-5.2 | Inkling | Claude Sonnet 4.6 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 83 | 76 | 81 |
| Price | 25% | 18 | 16 | 13 |
| Inputs & features | 15% | 70 | 70 | 80 |
| Context window | 10% | 44 | 61 | 60 |
| Overall | 100% | 61/100 | 59/100 | 62/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.2OpenAI | InklingThinking Machines | Claude Sonnet 4.6Anthropic |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 153.5 (best) | 148.6 | 152.3 |
| ECI rank | #38 of 148 (best) | #57 of 148 | #40 of 148 |
| GPQA DiamondGraduate-level science questions | 91.4% (best) | 88.3% | 87.4% |
| FrontierMath Tiers 1–3Research-level mathematics | 67.4% (best) | 33.3% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 96.1% (best) | 88.9% | 85.8% |
| SWE-bench VerifiedFixing real GitHub issues | 73.8% | — | 75.2% (best) |
| SimpleQA VerifiedShort factual questions | 37.1% | 40.3% (best) | 35.5% |
| Price per million tokens | |||
| Input | $1.75 (best) | $3.74 | $3.00 |
| Output | $14.00 | $9.36 (best) | $15.00 |
| Cached input | $0.175 (best) | $0.748 | $0.30 |
| Blended (3:1) | $4.81 (best) | $5.14 | $6.00 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official Thinking Machines API | Official Anthropic API |
| Limits | |||
| Context window | 400,000 tokens | 1,048,576 tokens (best) | 1,000,000 tokens |
| Max output | 128,000 tokens | 1,048,576 tokens (best) | 64,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | No | No | Yes |
| Audio | No | Yes | No |
| Video | No | No | No |
| Reasoning | Yeslow · medium · high · xhigh | Yeslow · medium · high · xhigh · max | Yeslow · medium · high · max |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | No | Yes |
| Availability | |||
| Weights | Proprietary | OpenApache-2.0 | Proprietary |
| API model ID | gpt-5.2 | thinkingmachines/Inkling:peft:262144 | claude-sonnet-4-6 |
| API providers | 21 | 23 | 41 (best) |
| Released | Dec 11, 2025 | Jul 15, 2026 | Feb 17, 2026 |
| Knowledge cutoff | Aug 31, 2025 | — | Aug 31, 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.2$45.50
- Inkling$56.12
- Claude Sonnet 4.6$60.00
Which should you choose?
Which is better: GPT-5.2, Inkling or Claude Sonnet 4.6?
It is close. Our weighted score puts them within 1 points (Claude Sonnet 4.6 62/100, GPT-5.2 61/100, Inkling 59/100), so choose by what matters most for your work: GPT-5.2 for raw capability and Inkling for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5.2, Inkling or Claude Sonnet 4.6?
GPT-5.2 is cheaper at $1.75 input / $14.00 output per million tokens (official OpenAI API price). Inkling costs $3.74 input / $9.36 output per million tokens (official Thinking Machines API price); Claude Sonnet 4.6 costs $3.00 input / $15.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $4.81 per million tokens for GPT-5.2 versus $5.14 for Inkling (1.1× as much) and $6.00 for Claude Sonnet 4.6 (1.2× as much).
Which scores higher on benchmarks?
GPT-5.2 scores higher on the Capabilities Index (ECI): GPT-5.2 153.5 (#38 of 148), Claude Sonnet 4.6 152.3 (#40 of 148) and Inkling 148.6 (#57 of 148). The confidence ranges of the top two overlap (151.7–155.4 vs 149.6–154.7), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-5.2 91.4%, Inkling 88.3%, Claude Sonnet 4.6 87.4%; OTIS Mock AIME 2024–2025 — GPT-5.2 96.1%, Inkling 88.9%, Claude Sonnet 4.6 85.8%; SimpleQA Verified — Inkling 40.3%, GPT-5.2 37.1%, Claude Sonnet 4.6 35.5%.
Which is better for coding?
There are no published SWE-bench Verified results for Inkling yet, so there is no like-for-like coding score. On overall capability, GPT-5.2 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
Inkling has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 4.6 and 400,000 for GPT-5.2. Maximum output per response: GPT-5.2 up to 128,000, Inkling up to 1,048,576, Claude Sonnet 4.6 up to 64,000 tokens.
Which can read images, PDFs, audio or video?
GPT-5.2 accepts text and images; Inkling accepts text, images and audio; Claude Sonnet 4.6 accepts text, images and PDFs. Inkling handles the widest range of inputs.
Are any of these open source?
Inkling publishes its weights (Apache-2.0) and can be self-hosted; GPT-5.2 and Claude Sonnet 4.6 is proprietary.
Which is newer?
Inkling is the newest, released Jul 15, 2026. Claude Sonnet 4.6 came out Feb 17, 2026; GPT-5.2 came out Dec 11, 2025. Knowledge cutoff: GPT-5.2 Aug 31, 2025, Claude Sonnet 4.6 Aug 31, 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
